Slight transmission shudder...

[ajs67donzi]

...usually from 2nd to 3rd gear, but sometimes from 3rd to 4th. It's only noticeable when light on the pedal, and it's not a violent shudder. When I'm firm on the gas it shifts like butter.

 

(2015 GMC Sierra 1500, 5.3L, Denali edition, Engine Code T, Truck # 6L90, 133k miles on it.)

 

Here's the puzzling part...5,000 miles ago I had the entire transmission replaced by a shop in Sebastian, Florida!

 

With the truck currently in Virginia, they suggest a few things to narrow it down. Shudder Fix because it is easy, and Chevron Techron in case it's a misfiring engine. The local auto store scanned for a code and found none. I also unplugged the AFM disabler.

 

I'm hoping this slight shudder is normal at a certain RPM while accelerating carefully, and that I am unnecessarily worried.

But, I wanted to see if anyone had any other thoughts.

 

Thanks in advance for any suggestions or opinions!

Edited August 24, 2022 by ajs67donzi

[Retired15]

I got 2014 Silverado with 35k been having similar issue since purchased. Dealer Tech said it was due to the low RPM vs speed the tyranny and the computer are caught like in-between actions. Applying more pressure on accelerator helps alleviate it. OK, but when in slow city traffic that action is not the answer, so you have to slow vehicle down to stop the vibration, this is very annoying. Other than that no issues accelerating for hwy entry or passing. Still, it is very annoying. 

[David Krueger]

Try changing the tranny fluid. I had a 2017 Colorado. developed shutter shift at 50,000 miles. Dealer wanted to charge me $500 to change tranny fluid. Did some research and found the new fluid is Mobil 1 Synthetic LV ATF HP Dexron. Bought the fluid and took it to my local garage. total cost $185.00 Shutter shift gone imediatly. Do some research online. Find the correct fluid for your truck. Good Luck.

[ajs67donzi]

I remain frustrated by this problem.

Definitely still shuddering, despite attempted mitigation.

 

Assumption is a defective torque converter, despite it being new and of a higher quality (CV-GM10405-S1).

My bad luck, apparently, compounded by the transmission shop being in Florida and the truck being in Virginia.

 

It's covered by an ATRA Warranty program, but my Florida guy has hesitations about taking it elsewhere.

He worries the shop might promise the upgraded torque converter, but install a less expensive model.

 

 

 

 

Edited September 1, 2022 by ajs67donzi

[ajs67donzi]

On 8/24/2022 at 12:39 PM, David Krueger said:

 Do some research online. Find the correct fluid for your truck. Good Luck.

 

My Florida guy is trying everything before acknowledging it's a bad torque converter.

Related to the suggestion above, he has me adding a Motorcraft product called "Additive Friction Modifier".

I'm hopeful, but not overly optimistic!